Crucible for alumino-thermic reactions for welding operations



March 31,1925. 1,532,100

J. H. DEPPELER- CRUCIBLE FOR ALUMINO THERMIC REACTIONS FOR WELDING OPERATIONS Filed April 10, 192.5

INVENTOR gx ,m

HIS ATTORNEY .Very slowly in a lateral Patented Mar. 31 1925.

1,532,100 UNITED STATES PATENT OFFICE;

I JOHN H. DEFPELER, 0F WEEHAWKEN, NEW JERSEY,

,ASSIG'NOR TO METAL & THERMIT CORPORATION, OF CHROME, NEW JERSEY, A CORPORATION OF NEW- JERSEY.

GRUGIBLE FOR ALUMINO-THERMIC REACTIONS FOR WELDING OPERATIONS.

Application filed April 10, 1923. Serial No. 631,151.

To all whom it may concern: a

Be it known that I, JOHN H. DEBPELER, a citizen of the United States, and a resident of Weehawken, in the county of Hudson and State of NewJersey, have invented certain new and useful Improvements in Crucibles for Alumino-Thermic Reactions for Welding Operations; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention ployed primarily in carrying out aluminothermic reactions for weldmg operations, and has for its object to construct a crucible of such form as will ensure the quiet and uniform propagation of the reaction after the latter has been initiated. Heretof ore, it has been the custom to em relatively long, narr0w, on the assumption that such a form of crucible was necessary in view of the fact that reaction of an alumino-thermic mass proceeds downwardly with great rapidity, and

direction. The exrelativel pedient of providing a deep, nar- 7 row body of thermit in the comcal crucible was followed on the assum tion that only by such an arrangement cou' d a rapid melting of the body of metal in the crucible be effected. It has been found, however, that the reaction is so violent, when carried out in such a body, that a considerable portion of the slag is erupted or thrown out of the cruciblewith. danger to the operator, and also to the impairment of the ultimate product, which is liable to contain some slag.

or example, it has been found that if a thermit mixture were ignited in a vertical pipe, the reaction would-be extremely vioshould be "quickly so that it will retain its superheat,

lent, blowing most of the contents out of the pipe, whereas if the same amount of the mixture were laid on" a fiat plate, the reaction would be propagated veryslowly, if at all. It is highly desirable, of course, to secure a quiet and complete reaction between the thermit and the metal to be melted, and at the same time to ensure the development and retention of the maximum heat within the mass until the superheated molten metal is discharged from the crucible. In welding operations, it is important that the reaction rapid, enough to melt the steel relates to crucibles em loy crucibles of conlcal constructlon,

latter will float but it is also important that the reaction should be quiet, so that the steel will quickly separate from the slag, and may be readily tapped from the crucible after the reaction, instead of continuing the reaction for some time attended by a more or less violent ebullition of the melting material, which, a. indicated, will render thesteel of an in ferior quality, and cause an admixture of the slag therewith, unless great care is taken.

he present invention contemplates the provision of a crucible of such form that the reaction will be propaga .quietly and with uniformity throughout the mass, thus eliminating the danger of spattering the contents, as well as the loss of material, and at the same time producing an excellent high quality thermit steel free from slag and entrapped gases. Such a crucible is shown in the accompanying drawing, in we represents the vation.

Referring to the drawing,

that the crucible comprises a which the figcrucible in sectional elebody of refractory material generally circular in cross sec tion with the sides 1 inclined inwardly to a slight degree from the vertical, and merging into a relatively broad, concave bottom 2, which is provided with a central tapping outlet 3, which latter is equipped with the usual refractory tubular stone 4, in which is applied the removable pering thimble 5. It has been ound that if the crucible be made'so that the maximum diameter is substantially equal to the height, so that the mass of the material to effect the alumino-thermic reaction within the crucible is comparatively wide at all transverse sections taken at right angles to the vertical axis of the crucible, the reaction when initiated at the surface will proceed downwardly and laterally throughout the mass, quietly and uniformly, without any tendency to throw any of the molten material out of the crucible, and the molten metal will qu'ickl settle and separate from the slag, whic on top of the molten metal, when the latter can be discharged from the bottom opening without danger of any admixture of slag therewit it will be noted and replaceable ta- While the crucible constituting the instant maximum diameter substantially equal to the height of the stood that these dimensions may be varied .invention has been described as having a vessel, it will be under-,

within reasonable limits without departing ing a shell of refractory material having 7 from the invention, so long as the crucible is a broad concave bottom provided With a, 10

constructed with a relatively broad bottom central pouring opening, the maximum diand with adiameter approximately equal t ameter of the shell being substantially equal 5 the height. to the height of the same.

hat-I claim is: In testimony whereof I affix my signature. A crucible for 'efl'ecting alumino-thermic reactions for welding operations, compris- JOHN H. DEPPELER. 

